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Tetralogy of Fallot (TOF)

Tetralogy of Fallot

What is tetralogy of Fallot? — Tetralogy of Fallot (also called "TOF") is a serious heart condition made up of 4 related heart problems (figure 1):
There is a hole between the 2 lower chambers (the "ventricles")
The main blood vessel that brings blood to the body (the "aorta") lies over the hole between the ventricles
The main blood vessel that goes to the lungs (the "pulmonary artery") is narrowed
The muscle of the lower right ventricle is thickened
These problems cause babies with TOF to have less oxygen in their blood than is normal. This can make the skin, lips, fingernails, and toenails look blue. Sometimes – for example, when the baby is upset or crying – the baby might turn very blue and even go limp or unconscious. This is called a "tet spell."
Most people who have TOF have a heart murmur. This is an extra sound doctors and nurses can hear when they listen to the heart with a stethoscope.
A person who has TOF is born with it. Most babies born with TOF only have that condition. But some people with TOF have other heart problems or health conditions.
How do doctors usually find TOF? — Doctors can find TOF before or after a baby is born. This can happen in the following ways:
Before the baby is born, with a test called an "ultrasound" – This test uses sound waves to create pictures of the fetus. Doctors and nurses do this test to see if the baby is healthy and growing normally. It can show TOF and other problems.
Just after the baby is born, if:
•The baby's skin, lips, fingernails, or toenails look blue
•A routine test called "pulse oximetry" shows the baby does not have enough oxygen in his or her blood – This test measures oxygen in the blood with a small device that goes on a finger.
When the baby or child is older, if:
•The baby's skin looks blue
•The baby has "tet spells" – These are times when a baby turns very blue, and might even go limp or unconscious. Tet spells usually happen when a baby is active, upset, or crying.
•The baby has a heart murmur
Should my child see a doctor or nurse? — If your child's skin, lips, or fingernails or toenails look blue, tell your doctor or nurse. This is very important if the blue color gets worse when your baby is crying or feeding.
Will my child need tests? — Yes. If the doctor or nurse thinks your baby or child has TOF, he or she will order tests. These include:
An echocardiogram – This test uses sound waves to create a picture of the heart as it beats. It can show if a child has TOF or another heart problem.
An electrocardiogram (ECG) – This test measures the electrical activity in the heart. It can show any abnormal activity from TOF.
A chest X-ray – A chest X-ray can show changes in the shape of the heart from TOF.
How is TOF treated? — Almost all children with TOF need surgery to fix the heart problems. Doctors usually do surgery before a baby is 1 year old.
Even if your child does not have symptoms, he or she needs surgery. This is because TOF can cause problems if the heart is not fixed.
Doctors do not find TOF in some people until they are adults. Adults who have TOF also need surgery.
What will my child's life be like? — Many children who have surgery for TOF can live normal lives. But they still have a risk of heart problems and other health problems later. For example, some children who had surgery for TOF can have problems learning or growing normally. They need regular checkups and tests to make sure the heart is working correctly and to help with any other problems.
All topics are updated as new evidence becomes available and our peer review process is complete.
This topic retrieved from UpToDate on: Mar 30, 2020.
Topic 83995 Version 7.0
Release: 28.2.2 - C28.105
© 2020 UpToDate, Inc. and/or its affiliates. All rights reserved.

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